1. Field of the Invention
The present invention relates to a method and an apparatus for detecting a position of a lead of an electric component, and a method of mounting an electric component, and particularly to the art of improving the speed of detection of the position.
2. Discussion of Related Art
There is known an electric component including a body and one or more leads extending from the body. For example, the lead or each of the leads extends from a surface of the body, in a direction perpendicular to the surface, such that a free end of the lead or each lead is positioned away from the surface. The electric component is, e.g., a connector, a relay, or a capacitor.
Japanese Patent No. 2,899,121 discloses an apparatus for detecting a position of a lead of an electric component. For example, when an electric component is mounted on a circuit substrate, a position of a lead of the electric component is detected, and a positional error or a bending of the lead is recognized based on the detected position, so that the electric component may be accurately connected to a prescribed connection position on the circuit substrate.
The lead-position detecting device disclosed in the above-indicated Japanese patent takes an image of a lead in a direction perpendicular to a lengthwise direction of a free end portion of the lead, obtains a shape of a transverse cross section of the free end portion of the lead, i.e., a cross section thereof taken along a plane perpendicular to the lengthwise direction thereof, and detects a position of the lead based on image data representing the taken image. The lead-position detecting device includes an illuminating device and an image-taking device which are provided at respective positions away from the free end portion of the lead in a direction perpendicular to the lengthwise direction thereof. The illuminating device includes a laser diode, a lens which diffuses a horizontal light emitted by the laser diode, and another lens which converts the diffused light into parallel rays, so that the parallel rays are incident to the free end portion of the lead in a direction perpendicular to the lengthwise direction of the lead. The image-taking device is provided by a linear-image sensor which includes a number of light-sensing elements arranged along a straight line which is spaced from the lead and is perpendicular to the lengthwise direction thereof. The linear-image sensor successively takes respective linear images of respective portions of the lead. The image taking device and the illuminating device are revolved as a unit by a revolving device about an axis line parallel to an axis line of the electric component, so that the image-taking device takes respective images of the lead in three directions contained in a plane perpendicular to the lengthwise direction of the lead. Three batches of image data representing the three images of the lead taken in the three directions are processed, that is, the three images obtained from the one lead are processed altogether, so as to determine a transverse-cross-sectional shape of the lead and additionally determine, based on the thus determined shape, a position of the lead.
However, when a position of a lead is obtained in the above-described manner, three batches of image data obtained from the one lead need to be processed. Thus, the conventional lead-position detecting manner is cumbersome and time-consuming.